Power line communication (PLC) systems carry data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution. Power line communications systems operate by impressing a modulated carrier signal on the wiring system. Power line communications can be used in a home to interconnect home computers, peripherals, and/or home entertainment devices that have a network port, such as an Ethernet port. For example, powerline adapter units plug into power outlets and establish a network connection using the existing electrical wiring in the home. The powerline adapter units are then coupled to the home devices, such as through Ethernet interfaces, which allows the devices to share video and data without running dedicated network cables throughout the home. Powerline adapter units in a home may use encryption, or other security protocols, for data security.